we have two ideologies in this country and you've got to pick one or the other." >> president obama is battling for his own second term. >> narrator: three and a half years after he came to washington on a promise of change... >> a different president obama out on the campaign trail today. >> narrator: barack obama returned to the campaign trail, himself changed. >> a difficult road ahead for the president. >> i think you see today a president obama with a thicker skin, more jaundiced eyes. has grown more skeptical, even cynical, perhaps, about washington. >> narrator: as he made the case for reelection, the man who promised to transcend differences emphasized them. >> if i said the sky was blue, they said no. if i said there were fish in the sea, they said no. they figured, "if obama fails, then we win." >> it's hard to believe that it is the same person who was talking about bringing red america and blue america together, because he is now a polarizing figure. >> because of their policies, the republicans messed up so bad... >> having seen the collapse around washington from the debt